Is this mantel built into the stone or set against the stone? Love it!

Fireplace stacked stone, mantel & screen

What is the size of the mantel? Thanks...build a under seat wood storage...Wood storage, rock face...wood storage...Stone and Wood...fireplace, wood storage underneath...hearth for wood...Wood mantle...Wood storage under bench...metal on mantel...Rock over fireplace and mantel...Fireplace wood bin